5-fluoro-1H-pyrazolo[3,4-b]pyridin-3-amine derivatives are known to be GSK-3 inhibitors (WO2004/013140).
Previous attempts at large scale production of 2-chloro-5-fluoronicotinamide, one of the key intermediates of the synthesis of 5-fluoro-1H-pyrazolo[3,4-b]pyridin-3-amine, was not reproducible due to the large amounts of catalyst and hydrogen gas required. Moreover, large scale synthesis of the intermediate resulted in a mixture of starting material and product, which required separation.
Accordingly, the need exists for a process for the facile synthesis of 5-fluoro-1H-pyrazolo[3,4-b]pyridin-3-amine to obtain 5-fluoro-1H-pyrazolo[3,4-b]pyridin-3-amine derivatives in high yield and purity.